GB209897A - Improvements in or relating to weighing balances - Google Patents

Abstract

209,897. Dews, S., and Dews, G. Nov. 24, 1922. Taring-devices; loose-weight apparatus. - A weighing-balance is provided with means whereby a series of receptacles of varying weight placed upon a scale pan are balanced by an automatic adjustment made on a second scale pan so that the same conditions prevail as if all the receptacles were of the same weight. Means are also provided to render the adjusting device inoperative and to load the second scale pan with a definite predetermined weight. As shown, the invention comprises a centrally-pivoted beam a having at one end a scale pan b upon which receptacles are placed, and at the other end a support c carrying a master weight e to balance the material to be placed in the receptacle, an annular weight d approximating to the weight of the receptacle, and a liquid receiver l, the contents of which are adjusted to complete the balance of the receptacle. The master weight e is raised from the support c by a plunger f, the lower end of which rests on the surface of a cam g carried on a shaft h and operated by a handle k. If the weight on the support c is insufficient to balance the receptacle, the beam will tilt and a contact spring i, Fig. 4, will rise and complete a circuit with a contact q, thus energizing a magnet o, which varies a valve m and allows liquid to flow from a reservoir w into the receiver l until the beam is balanced when the circuit is automatically broken. Alternatively, if the weight on the support c is too great, a contact j will engage a contact r, thus completing a circuit through a magnet p and allowing liquid to flow from the receiver l into a sump S until balance is restored. Balance having been effected, the operator turns the handle k, which lowers the master weight on to the support and simultaneously by the engagement of cams r<2>, q<2> with levers r<1>, q<1> causes the contacts r, q to be moved respectively downwardly and upwardly out of engagement with the contacts j, i. The substance to be weighed is then poured into the receptacle until the beam balances. Two automatic cut-out switches s are provided to ensure that whichever one of the balancing circuits is closed, the other is rendered inoperative during the remainder of the adjustment. A pump v is connected to the end of the shaft h to return liquid from the sump S to the reservoir w.